Method and apparatus for placing a medical agent into a vessel of the body

ABSTRACT

A method and apparatus for placing a medical agent, such as an embolic coil into a vessel, or aneurysm, by utilizing a stabilizing catheter to retain or support a medical agent deployment device.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention concerns a novel method and apparatus for placing amedical agent into a vessel of the body, and in particular concerns anovel method for placing embolic coils within an aneurysm of the brain.

2. Description of the Prior Art

The use of embolic coils placed within an aneurysm for treating theaneurysm within the brain is well known. Various devices are known fordelivering embolic coils through the patient's vessel to the aneurysm.Typically these embolic coils, which generally take the form ofhelically wound coils, or random wound coils, are carried by a coildeployment device which serves to introduce the coils into the aneurysm.The coils are then released by the coil deployment device using one ofvarious types of release mechanisms.

An example of such a coil deployment device is disclosed in U.S. Pat.No. 6,113,622 entitled, “Embolic Coil Hydraulic Deployment System”,issued Sep. 5, 2000 and assigned to the same assignee as the presentpatent application. The disclosure of this patent is incorporated hereinand made a part of this application. It has been found to be difficultto place these coils in the exact desired position because of therelative lack of stability of the deployment device within the vesselduring the introduction of the embolic coil to an aneurysm. An exampleof a delivery system used to stabilize a coil deployment device isdisclosed in U.S. patent application Ser. No. 09/878,530, entitled“Delivery System Using Balloon Catheter”, filed Jun. 11, 2001 andassigned to the same assignee as the present patent application. Thedisclosure in this patent application is incorporated by reference andis made a part of the subject patent application.

It is, therefore, an object of this invention to provide a method forplacing embolic coils in a relatively precise manner by the use of astabilizing delivery catheter.

Another object of the present invention is to provide a method forplacing embolic coils within an aneurysm of the brain, which system isrelatively simple in use for the physician.

A further object of the present invention is to provide a method fordelivering medical agents such as diagnostic or therapeutic agents, andother medical agents by the use of a delivery catheter in a relativelysimple, efficient and stable manner.

A still further object is to provide a delivery catheter which enablesthe delivery of embolic coils within an aneurysm in a relatively simple,efficient and stable manner.

Another object of the present invention is to provide a deliverycatheter which may be utilized to deliver embolics, diagnostic, andtherapeutic agents by way of a delivery lumen.

A further object of the present invention is to provide a deliverycatheter that is relatively simple in construction.

Other objects of the present invention will become apparent from thefollowing description.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, there isprovided a method for placing an embolic coil into an aneurysm. Themethod includes the use of a delivery catheter having a proximalsection, a distal section and an intermediate section which is formedfrom a very flexible polymeric material. The catheter includes a firstlumen and a second lumen having a side opening at a location within theintermediate section of the delivery catheter. The catheter alsoincludes a pre-shaped retaining wire which extends through the firstlumen for shaping the intermediate section into a generally U-shapedconfiguration. The method includes the steps of inserting astraightening wire into the second lumen of the catheter to cause theintermediate section of the catheter to become relatively straight,introducing the delivery catheter into the vessel of a patient togenerally align the side opening with an aneurysm, withdrawing thestraightening wire from the second lumen to cause the intermediatesection of the delivery catheter to return to the U-shaped configurationat a location proximal to the aneurysm to thereby cause the side openingto move to a position adjacent to the aneurysm, introducing an emboliccoil deployment system into the proximal end of the delivery catheterthrough the second lumen and then through the side opening into theaneurysm. The method also includes the steps of delivering the emboliccoil into the aneurysm with the coil deployment system, withdrawing theembolic coil deployment system from the delivery catheter, againinserting the straightening wire into the second lumen of the catheterto cause the intermediate section to become relatively straight, andthereafter withdrawing the delivery catheter from the vessel of thepatient.

In accordance with the present invention there is also provided a methodfor placing a medical agent within a vessel. The method utilizes adelivery catheter having a proximal section, a distal section and anintermediate section which is formed of a polymeric material which isrelatively flexible, and in which the intermediate section is normallyshaped in a generally U-shaped, or bowed, configuration. In addition,the catheter has a first lumen and a second lumen having a side openingat a location within the intermediate section of the delivery catheter.The method includes the steps of inserting a guidewire into the secondlumen of the catheter to thereby cause the intermediate section of thecatheter to straighten, introducing the catheter into the vessel of apatient to generally align the side opening at a preselected positionwithin the vessel, withdrawing the guidewire to thereby permit theintermediate section of the catheter to straighten, introducing amedical agent deployment device into the second lumen of the deliverycatheter and through the side opening to deliver a medical agent at thepreselected position, reinserting a guidewire into the second lumen ofthe delivery catheter to thereby again cause the intermediate section ofthe catheter to straighten, and thereafter withdrawing the deliverycatheter from the vessel of the patient.

In accordance with still another aspect of the present invention, themedical agent takes the form of a diagnostic agent, a therapeutic agentor such device such as an embolic coil.

In accordance with still another aspect of the present invention thereis provided a method for placing an embolic coil into an aneurysm. Themethod utilizes a delivery catheter which has a proximal section, adistal section and an intermediate section which is formed from a veryflexible polymeric material. The intermediate section is normally shapedinto a generally U-shaped, or bowed configuration. The catheter alsoincludes a first lumen and a second lumen having a side opening at alocation within the intermediate section of the delivery catheter. Themethod also incorporates a coil deployment device which includes anelongated flexible deployment catheter having a lumen extendingtherethrough and having a distal section being formed of a material of adurometer which exhibits the characteristics that when a fluid pressureis applied to the lumen of the deployment catheter the walls of thedistal section expand outwardly. The coil deployment device in additionincludes an embolic coil which is disposed in fluid tight engagementwithin the lumen o the distal section of the device. In addition, thecoil deployment device includes a source of pressure coupled to theproximal section of the device for applying a fluid pressure to thelumen of the coil deployment device. The method includes the steps ofinserting a straightening wire into the second lumen of the catheter tocause the intermediate section of the catheter to become relativelystraight, introducing the delivery catheter into the vessel of a patientto generally align the second opening with an aneurysm, withdrawing thestraightening wire from the second lumen of the delivery catheter tocause the intermediate section to return to the U-shaped configurationat a location proximal to the aneurysm to thereby cause the side openingto move to a position adjacent the aneurysm. The method also includesthe steps of introducing the embolic coil deployment device into theproximal end of the delivery catheter through the second lumen andthrough the side opening into the aneurysm, applying a pressure withsaid source of pressure to the lumen of the deployment device to therebycause the walls of the distal section of the deployment device to expandand release the embolic coil, withdrawing the embolic coil deploymentdevice from the delivery catheter, again inserting the straighteningwire into the second lumen of the catheter to cause the intermediatesection to become relatively straight and thereafter withdrawing thedelivery catheter from the vessel of the patient.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial sectional view of a delivery catheter constructed inaccordance with the principles of the present invention;

FIG. 2 is a partial sectional view of a vascular occlusive coildeployment system that may be used with the delivery catheter of FIG. 1;

FIG. 3 is a side elevational view of the delivery catheter of FIG. 1 inuse to delivery an embolic coil to an aneurysm;

FIG. 4 is a cross-sectional view of the catheter of FIG. 3, taken alongthe plane of the line 5-5′ of FIG. 3;

FIG. 5 is a cross-sectional view of the catheter of FIG. 3, taken alongthe plane of line 5-5′ of FIG. 3; and,

FIGS. 6 through 9 are diagrammatic sequential views of a method ofplacing embolic coils in accordance with an embodiment of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 generally illustrates the construction of a preferred embodimentof the delivery catheter of the present invention which generallycomprises a dual lumen catheter 10 having a “Y” connector 12 coupled tothe proximal end of the catheter. More particularly, the dual lumencatheter includes a first lumen 14 and a second lumen 16. The secondlumen 16 extends from the proximal end of the catheter to the distal endof the catheter and also communicates with a lumen 18 which extends fromthe distal end to the proximal end of the “Y” connector 12. Asillustrated, a side opening 20 extends from the second lumen 16 throughthe side wall of the catheter at a position which is slightly proximatethe distal tip of the delivery catheter 10. This side opening, as willbe subsequently explained in more detail, serves to permit theintroduction of an embolic coil deployment device into an aneurysm forplacement of an embolic coil into the aneurysm.

As further illustrated in FIG. 1, the first lumen 14 and a second lumen16 extend through the delivery catheter 10. In addition, the proximalend of the first lumen 14 and the second lumen 16 communicate withpassageways in the “Y” connector 12 and extend out of the side port 22and the proximal end respectively of the “Y” connector 12.

While the delivery catheter 10 may be constructed of various flexiblematerials including various polymers, preferably, the catheter 10 isformed in three different sections of materials having differentdurometers and different polymer compositions. The proximal section ofthe catheter 23A, designated as “A”, is preferably formed of a nylonmaterial having a durometer of about 75D and extends for a length ofabout 100 centimeters. The intermediate section 23B, designated as “B”,is preferably formed of a pebax material having a durometer of about 40Dand is generally about 40 centimeters in length, and the distal section23C of the catheter, designated as “C”, is preferably formed of apellethane material having a durometer of about 80A and extends for alength of about 10 centimeters. With this construction the catheter issufficiently flexible to be delivered through the various tortuousvessels of the human brain but at the same time provides sufficientrigidity or “back-up” support for introducing the catheter into andthrough these vessels. This construction also makes possible the ease ofdeflection, or bowing, of the intermediate section 23B.

As may be seen, the delivery catheter also includes a pre-shaped wire 23which is disposed in the first lumen 14. The wire 23 is bent, or bowed,in the region of the intermediate section to thereby cause theintermediate section to be bowed thereby causing the side opening to bemoved laterally away from the center line of the catheter.

FIG. 2 illustrates a hydraulic occlusive coil deployment device 100which is comprised of a hydraulic injector, or syringe, 102, coupled tothe proximal end of a positioning catheter 104. An embolic coil 106 isdisposed within the lumen at the distal section 108 of the catheter. Theproximal end of the coil 106 is tightly held within the lumen of thedistal section 108 of the catheter 104 until the deployment device isactivated for release of the coil. As may be seen, the syringe 102includes a threaded piston 110 which is controlled by the handle 112 forinfusing fluid into the interior of the catheter 104. Also, asillustrated, the catheter 104 includes a winged hub 114 which aids inthe insertion of the catheter.

The embolic coil 106 may take various forms and configurations, and mayeven take the form of a randomly wound coil. Preferably, the distalsection of the coil deployment device 100 is formed of a polymericmaterial with a relatively low durometer which exhibits thecharacteristic that, when a fluid pressure of approximately 300 psi isapplied to the interior of the catheter, the walls of the distal section108 expand radially, somewhat similar to the action of a ballooninflating, to thereby release the proximal end of the coil 106.Reference is made to the above-mentioned U.S. Pat. No. 6,113,622 for amore detailed description of the hydraulic occlusive coil deploymentdevice 100.

FIG. 3 illustrates in detail the delivery catheter 10 which has beeninserted into a blood vessel 26 of the brain in order to place anembolic coil 106 into an aneurysm 28. FIGS. 4 and 5 illustratecross-sections taken through the delivery catheter 10 at locationsindicated by 4-4′ prime and 5-5′, respectively, shown in FIG. 3.

More particularly, FIG. 4 in conjunction with FIG. 3 illustrates thelocation where the pre-shaped wire 23 is bowed to cause the deliverycatheter to be normally shaped in a generally U-shaped configuration atthe intermediate section 23B of the catheter. Also illustrated in FIG. 4is an end view of the embolic coil deployment device which extendsthrough the side opening 20 of the catheter 10. FIG. 5 illustrates asectional view of the delivery catheter 10 with the pre-shaped wire 23disposed in the first lumen 14.

Reference is made to FIGS. 3 and 6 through 9 for an understanding of theoperation of the delivery catheter used in conjunction with the emboliccoil deployment device 100. As illustrated in FIG. 6, the deliverycatheter is inserted into a vessel, over a stiffening guidewire 32, andis positioned such that the side opening 20 is adjacent to an aneurysm28. The guidewire 32 is then removed and as illustrated in FIG. 7, thedelivery catheter 10 deflects, or bows, in the region where the sideopening 20 is located to thereby cause the side opening to essentiallymate with the opening of the aneurysm 28. Once the side opening 20 hasbeen positioned at the mouth of the aneurysm 28, the embolic coildeployment device 100 may then be inserted through the second lumen andthen out of the side opening 20 and into the aneurysm 28 as illustratedin FIG. 8. Then the embolic coil 106 may be placed into the aneurysm andreleased from the distal end of the deployment device 100.

The deployment device 100 may then be removed and this process may berepeated until such time as sufficient coils have been placed into theaneurysm. When the aneurysm 28 has been sufficiently filled with emboliccoils, the coil deployment device may be removed from the deliverycatheter. Thereafter, the stiffening guidewire 32 may be inserted intothe second lumen 16 to thereby cause the delivery catheter to straightenwithin the vessel. Once the catheter has straightened, the catheter maybe easily withdrawn from the vessel and from the body of the patient.

Alternatively, the delivery catheter may be constructed with a shaperetaining wire disposed in the first lumen 14 as opposed to thepre-shaped wire 23, and in this case the physician may pre-shape theintermediate section 23B into a generally U-shaped configuration priorto use.

In still another alternative construction, the delivery catheter may bea single lumen catheter having neither a pre-shaped wire 23 nor a shaperetaining wire, but the catheter body is formed of a shape retainingpolymer which may be heat set to form a U-shaped intermediate section,either when the catheter is manufactured or by the physician prior touse by the physician.

As may be appreciated, with the present invention it is possible tostabilize the delivery catheter at a position where the side opening ofthe delivery catheter is adjacent to the aneurysm. Embolic coils may bedelivered through the side opening of the delivery catheter directlyinto the aneurysm with relatively good precision. With this system it ispossible to fill an aneurysm with a plurality of embolic coils in veryshort order without the loss of coils into the main blood vessel, orother vessels within the body. These and other advantageous of thisinvention will become more apparent from an understanding of theinvention as claimed.

A novel system and method have been disclosed in which an embolic coil,or coils, may be securely placed within an aneurysm with a deliverycatheter which is stabilized. Although an illustrative embodiment of theinvention has been shown and described, it is to be understood thatvarious modifications and substitutions may be made by those skilled inthe art without departing from the spirit and scope of the presentinvention.

Further, in addition to the delivery of embolic coils, the system may beutilized to deliver other medical agents such as diagnostic ortherapeutic agents of various types including liquid embolic materials.Other modifications may be made which would be within the spirit and thescope of the following claims.

1-2. (canceled)
 3. A method for placing a medical agent within a vesselcomprising the steps of: providing a delivery catheter having a proximalsection, a distal section and an intermediate section which is formedfrom a relatively flexible polymeric material, said intermediate sectionbeing normally shaped in a generally bowed configuration; and saidcatheter having a first lumen and a second lumen with a side opening ata location within the intermediate section; preloading the second lumenof the delivery catheter with a guidewire extending through said secondlumen to thereby cause the intermediate section of the catheter tostraighten; introducing the catheter into the vessel of a patient togenerally align the side opening at a preselected position within thevessel; withdrawing the guidewire to thereby permit the intermediatesection of the catheter to straighten; introducing a medical agentdeployment device into the second lumen of the delivery catheter andthrough the side opening to deliver the medical agent at the preselectedposition; reinserting the guidewire into the second lumen of thedelivery catheter to thereby again cause the intermediate section of thecatheter to straighten; and, thereafter withdrawing the deliverycatheter from the vessel of the patient.
 4. A method as defined in claim3, wherein said medical agent comprises a diagnostic agent.
 5. A methodas defined in claim 3, wherein said medical agent comprises atherapeutic agent.
 6. A method as defined in claim 3, wherein saidmedical agent comprises an embolic coil. 7-13. (canceled)